As you're probably aware, there are four international regimes now with the ATT that added a fifth qualitative measure on the regimes that are currently in place. Those include things such as the Wassenaar agreement that lay baseline benchmarks against which all parties to the regimes assess export-control permits.
However, the interpretation of those benchmarks is then ultimately a function of sovereignty. Even within that legislation—that sovereignty—all of those countries still accord considerable discretion to the ministers or secretaries of state when it comes to foreign affairs. This is precisely because, for all of those countries, arms exports of defence technology is an instrument of foreign policy.